Our Alloys

Martensitic Stainless Steels are used extensively in sweet (CO2) environments where carbon and low alloy steels experience general corrosion from the effects of CO2, H2S, chlorides, pH, and temperature. Standard 13 Chrome and Super 13 Chrome are approved for slightly sour environments in accordance with NACE MR0175/ISO 15156.

Martensitic Stainless Steels are quenched and tempered, resulting in a yield strength ranging from 80 – 140 ksi.

13 Chrome

UNS S42000
Corrosion Resistance: Mild
13CR-L80 Datasheet13CR-L80 Alloy Guide


13 Chrome (UNS S42000), referred to as L80-13Cr, is the least alloyed of the stainless steels and most commonly used for OCTG. 13 Chrome is best suited for corrosion resistance in sweet (CO2) environments and mild sour environments within the guidelines of NACE MR0175/ISO 15156. Higher alloys are required where chlorides or oxygen are present as 13 Chrome is prone to pitting corrosion in these conditions.

13 Chrome has a controlled yield strength and hardness requirement and is classified as Group 2, Grade L80, Type 13Cr per API 5CT. Learn More Here.

Modified 13 Chrome / HP-1

Corrosion Resistance: Mild
13CRM/HP-1 Datasheet


Modified 13 Chrome and 13 Chrome HP-1, also referred to as Hyper I, are used in sweet (CO2) environments, where carbon and low alloy steels experience general corrosion, offering higher strength and improved resistance to the effects of CO2, H2S, chlorides, pH, and temperature when compared to API L80-13CR. Though their chemical compositions slightly differ, 13CRM and HP-1 perform equally in applicable environments.

NACE MR0175/ISO15156 does not provide guidance for use of these alloys in sour service.

Super 13 Chrome

UNS S41426
Corrosion Resistance: Mild
13CRS Datasheet


Super Chrome 13 (S41426) is used in sweet (CO2) environments and mild sour (H2S) environments where carbon and low alloy steels experience general corrosion, offering higher strength and improved resistance to the effects of CO2, H2S, chlorides, pH, and temperature when compared to API L80-13CR. This higher temperature threshold and yield strength mean it is often used in deeper, high-pressure, high-temperature (HPHT) conditions as downhole tubular components, packers, and other subsurface equipment.

NACE MR0175/ISO15156 Table A.19 provides a recommended limit of 1.5 psi partial pressure H2S. API 5CRA/ISO13680 classifies it as Group 1, Category 13-5-2 alloy acceptable for sour service, in the 95 ksi yield strength condition.

13 Chrome HP-2

Corrosion Resistance: Mild
13CR-HP2 Datasheet


13CR-HP2, also known as Hyper 2, is used in sweet (CO2) environments where low-alloy and carbon steels would be susceptible to general and/or localized corrosion. 13 Chrome HP-2 offers improved mechanical properties, higher yield strength, and greater resistance to the effects of CO2, H2S, chlorides, pH, and temperature when compared to API L80-13CR. This higher temperature threshold and yield strength mean it is often used in deeper, high-pressure, high-temperature (HPHT) conditions as downhole tubular components, packers, and other subsurface equipment.

NACE MR0175/ISO15156 does not provide guidance for use of these alloys in sour service. API 5CRA/ISO13680 classifies it as PSL-1, Group 1, Category 13-5-2 alloy.

15 Chrome

Corrosion Resistance: Mild
15 Chrome Datasheet


15 Chrome, or Super 15 Chrome, is suitable for high-pressure, high-temperature (HPHT) wells where high-strength OCTG is required. In addition to extending the temperature range, 15 Chrome provides improved performance compared to the 13 Chrome Alloys in chloride and sweet (CO2) environments.

Super 15 Chrome, grade 125, is not recommended for sour service.

17 Chrome

Corrosion Resistance: Mild
17 Chrome Datasheet


17 Chrome is intended for high-pressure, high-temperature (HPHT) wells where high-strength OCTG is required. In addition to extending the temperature range, 17 Chrome provides improved performance compared to the 13 Chrome Alloys in chloride and sweet (CO2) environments. 17 Chrome is not recommended for sour service.

Duplex Stainless Steels are used in sweet (CO2) environments containing high chlorides or dissolved oxygen where pitting and crevice corrosion are a concern, sweet (CO2) high-pressure, high-temperature (HPHT) environments, and slightly sour conditions within the guidelines of NACE MR0175/ISO 15156.

Super Duplex Stainless Steels, defined by a PREN (Pitting Resistance Equivalence) greater than 40, extend the useful range of Duplex Stainless Steels in environments with high chlorides or dissolved oxygen, such as seawater or water injection wells.

22 Chrome

UNS S31803
Corrosion Resistance: Moderate
22CR Datasheet


22 Chrome (UNS S31803), also referred to as 2205 Duplex, is a premium duplex stainless steel intended for sweet (CO2) wells containing chlorides and low levels of H2S.

22 Chrome offers high resistance to pitting and crevice corrosion, making it a common choice for high-pressure, high-temperature (HPHT) applications where localized corrosion is a concern.

This alloy is classified in MR0175/ISO15156 as a duplex stainless steel having Pitting Resistance Equivalent Number (PREN) ≤ 40 and is suitable for H2S partial pressure ≤ 0.3 psi.

25 Chrome

UNS S31260
Corrosion Resistance: Moderate
25CR Datasheet


25 Chrome (UNS S31260), also referred to as 2507 Duplex, is a premium duplex stainless steel intended for wells containing high CO2, low H2S, and chlorides. 25 Chrome offers high resistance to pitting and crevice corrosion, making it a common choice for high-pressure, high-temperature (HPHT) applications where localized corrosion is a concern.

This alloy is classified in MR0175/ISO15156 as a duplex stainless steel having a Pitting Resistance Equivalent Number ≤ 40 and is suitable for H2S partial pressure ≤ 0.3 psi.

25CRS

UNS S32760
Corrosion Resistance: Moderate
25CRS Datasheet


25CRS (UNS S32760), also referred to as Super Duplex 25 Chrome, is a super duplex stainless steel suitable for high chloride and mildly sour wells with partial pressure of H2S ≤ 3 psi. With a Pitting Resistance Equivalent Number ≥ 40, 25CRS provides outstanding resistance to pitting and crevice corrosion in the presence of high chlorides or dissolved oxygen and is often used in seawater and water injection wells.

25CRW

UNS S39274
Corrosion Resistance: Moderate
25CRW Datasheet


25CRW (UNS S39274), also referred to as Super Duplex 25 Chrome, is a Super Duplex Stainless Steel suitable for use in high chloride and mildly sour wells with partial pressure of H2S ≤ 3 psi.

With a Pitting Resistance Equivalent Number ≥ 40, 25CRW provides outstanding resistance to pitting and crevice corrosion in the presence of high chlorides or dissolved oxygen and is often used in seawater, water injection wells, and high-pressure, high-temperature (HPHT) applications concerned with localized corrosion.

Solid Solution Nickel Base Alloys are used primarily in sour environments where the partial pressure of H2S exceeds 3 psi. Their useful range of temperature, H2S, and chlorides is extended by increasing additions of nickel, molybdenum, and other elements. In addition to excellent resistance to chlorides and H2S, they eliminate the risk of hydrogen embrittlement that can occur with heat-treated alloys. 

These alloys are typically used in severely corrosive environments and are available in cold-worked condition with yield strengths up to 160 ksi. 

28 Chrome

UNS N08028
Corrosion Resistance: High
28 Chrome Datasheet


28 Chrome (UNS N08028) is a solid solution nickel-based alloy, capable of meeting the severe challenges of high-pressure, high-temperature (HPHT) sour wells.

The alloy is classified in MR0175/ISO15156 as a type 4c alloy, with no restrictions to partial pressure of H2S below 270°F and resistant to 100 psi H2S at 425°F.

2535

UNS N08535
Corrosion Resistance: High
2535 Datasheet


Alloy 2535 (UNS N08535) is typically supplied as a cold-worked solid solution nickel base alloy required for critical well conditions combining high concentrations of CO2, H2S, and Chlorides. The alloy is classified in MR0175/ISO15156 as a type 4c alloy, with no restrictions to partial pressure of H2S below 270°F and resistant to 100 psi H2S at 425°F.

Alloy 2535 is primarily used in severely corrosive environments such as sections permanently exposed to production/injection fluids and is capable of meeting the severe challenges of high-pressure, high-temperature (HPHT) sour wells.

Among wrought stainless steels, the composition of Alloy 2535 is notable for containing comparatively high amounts of chromium (Cr) and nickel (Ni). With a typical Pitting Resistance Equivalent Number of 36, Alloy 2535 is highly resistant to environmental stress corrosion cracking.

CRA 825

UNS N08825
Corrosion Resistance: High
825 Datasheet


CRA 825 (UNS N08825), also referred to as 2242, is typically supplied as a cold-worked solid solution nickel-based alloy, capable of meeting the severe challenges of high-pressure, high-temperature (HPHT) sour wells. CRA 825 has excellent resistance to stress corrosion cracking (SSC) and to localized attack such as pitting and crevice corrosion.

The alloy is classified in MR0175/ISO15156 as a type 4c alloy, with no restrictions to partial pressure of H2S below 270°F and resistant to 100 psi H2S at 425°F.

G3

UNS N06985
Corrosion Resistance: Severe
G3 Datasheet


CRA G3 (UNS N06985) is a cold-worked nickel-based alloy meeting the severe challenges of wells containing high chlorides, H2S, and temperature.

For sour service applications, it is classified in MR0175/ISO15156 as a type 4d alloy, with no restrictions to partial pressure of H2S below 300°F and resistant to 300 psi H2S at 425°F.

G2

UNS N06975
Corrosion Resistance: Severe
G2 Datasheet


CRA G2 (UNS N06975) is typically supplied as a cold-worked solid solution nickel-based alloy meeting the severe challenges of wells containing high chlorides, H2S, and temperature. With a typical Pitting Resistance Equivalent Number of 51, it is highly resistant to pitting corrosion and chloride-induced stress corrosion cracking.

For sour service applications, it is classified in MR0175/ISO15156 as a type 4d alloy, with no restrictions to partial pressure of H2S below 300°F and resistant to 300 psi H2S at 425°F.

CRA 2550E

UNS N06255
Corrosion Resistance: Severe – Extreme
CRA 2550E Datasheet2550 Datasheet


CRA 2550E (UNS N06255), also known as Alloy 2550, is typically supplied as a cold-worked solid solution nickel-based alloy used in severely corrosive environments containing high chlorides, dissolved oxygen, H2S, and temperature. CRA 2550E is generally immune to concentrations of CO2 and limited mostly by H2S content and temperature. With a typical Pitting Resistance Equivalent Number of 47, it is highly resistant to pitting corrosion and chloride-induced stress corrosion cracking.

For sour service applications, it is classified in MR0175/ISO15156 as a type 4d alloy, with no restrictions to partial pressure of H2S below 300°F and resistant to 300 psi H2S at 425°F.

CRA 2550E has excellent hydrogen embrittlement resistance at all standard strength levels.

C276

UNS N10276
Corrosion Resistance: Extreme
C276 DatasheetC276-160 Datasheet


C276 (UNS N10276) is a cold-worked solid solution nickel-based alloy used to meet the severe challenges of high-pressure, high-temperature (HPHT) sour wells. With a typical Pitting Resistance Equivalent Number of 75, C276 is highly resistant to pitting corrosion and chloride-induced stress corrosion cracking (SSC).

The alloy is classified in MR0175/ISO15156 as a type 4e alloy, with no restrictions to partial pressure of H2S below 270°F and resistant to 1000 psi H2S at 450°F.